TAR hallmark identification

[morhathol]

Hello, I've just registered after not finding what I needed on the website. My girlfriend found a ring today in a craft store in a component bin. She liked it and bought it for a few cents, and when she showed it to me she asked whether it could be silver. There are hallmarks indeed, though I didn't find any info on the internet, so I thought I'd ask. It's not that important to know, but I'm curious now that she told me. I'm guessing it could be of European origin, as it was found in Slovakia. Could anyone please help with identifying?



In case the hallmarks are not visible enough (I don't have the best conditions to photograph such small things), the one in question is "TAR" in a slightly flattened hexagon.

Thanks in advance for your time!

Roman